From af60e10c4f4ba31f4b1c37a30da5ef822d5957f7 Mon Sep 17 00:00:00 2001
From: Alex Shinn <ashinn@users.noreply.github.com>
Date: Thu, 2 Feb 2012 23:16:16 +0900
Subject: [PATCH] Now that bugs are fixed, re-using same stack for eval. 
 Restores stack traces.

---
 eval.c | 6 ++++--
 vm.c   | 7 ++++++-
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/eval.c b/eval.c
index ca646af4..2a6df2fb 100644
--- a/eval.c
+++ b/eval.c
@@ -1147,7 +1147,7 @@ sexp sexp_load_op (sexp ctx, sexp self, sexp_sint_t n, sexp source, sexp env) {
   }
   sexp_gc_preserve4(ctx, ctx2, x, in, res);
   out = sexp_current_error_port(ctx);
-  ctx2 = sexp_make_eval_context(ctx, NULL, env, 0, 0);
+  ctx2 = sexp_make_eval_context(ctx, sexp_context_stack(ctx), env, 0, 0);
   sexp_context_parent(ctx2) = ctx;
   tmp = sexp_env_bindings(env);
   sexp_context_tailp(ctx2) = 0;
@@ -1163,6 +1163,7 @@ sexp sexp_load_op (sexp ctx, sexp self, sexp_sint_t n, sexp source, sexp env) {
       if (sexp_exceptionp(res))
         break;
     }
+    sexp_context_last_fp(ctx) = sexp_context_last_fp(ctx2);
     if (x == SEXP_EOF)
       res = SEXP_VOID;
     sexp_close_port(ctx, in);
@@ -2138,6 +2139,7 @@ sexp sexp_compile_op (sexp ctx, sexp self, sexp_sint_t n, sexp obj, sexp env) {
     res = sexp_make_procedure(ctx2, SEXP_ZERO, SEXP_ZERO, res, vec);
   }
   sexp_context_child(ctx) = SEXP_FALSE;
+  sexp_context_last_fp(ctx) = sexp_context_last_fp(ctx2);
   sexp_gc_release3(ctx);
   return res;
 }
@@ -2152,7 +2154,7 @@ sexp sexp_eval_op (sexp ctx, sexp self, sexp_sint_t n, sexp obj, sexp env) {
   top = sexp_context_top(ctx);
   params = sexp_context_params(ctx);
   sexp_context_params(ctx) = SEXP_NULL;
-  ctx2 = sexp_make_eval_context(ctx, NULL, env, 0, 0);
+  ctx2 = sexp_make_eval_context(ctx, sexp_context_stack(ctx), env, 0, 0);
   sexp_context_child(ctx) = ctx2;
   sexp_context_dk(ctx2) = sexp_list1(ctx, SEXP_FALSE);
   res = sexp_compile_op(ctx2, self, n, obj, env);
diff --git a/vm.c b/vm.c
index b7d60935..ed7fc61f 100644
--- a/vm.c
+++ b/vm.c
@@ -29,7 +29,7 @@ void sexp_stack_trace (sexp ctx, sexp out) {
     if (self && sexp_procedurep(self)) {
       sexp_write_string(ctx, "  called from ", out);
       bc = sexp_procedure_code(self);
-      if (sexp_truep(sexp_bytecode_name(bc)))
+      if (sexp_symbolp(sexp_bytecode_name(bc)))
         sexp_write(ctx, sexp_bytecode_name(bc), out);
       else
         sexp_write_string(ctx, "<anonymous>", out);
@@ -1050,24 +1050,28 @@ sexp sexp_apply (sexp ctx, sexp proc, sexp args) {
   case SEXP_OP_FCALL1:
     _ALIGN_IP();
     sexp_context_top(ctx) = top;
+    sexp_context_last_fp(ctx) = fp;
     tmp1 = ((sexp_proc2)sexp_opcode_func(_WORD0))(ctx, _WORD0, 1, _ARG1);
     sexp_fcall_return(tmp1, 0)
     break;
   case SEXP_OP_FCALL2:
     _ALIGN_IP();
     sexp_context_top(ctx) = top;
+    sexp_context_last_fp(ctx) = fp;
     tmp1 = ((sexp_proc3)sexp_opcode_func(_WORD0))(ctx, _WORD0, 2, _ARG1, _ARG2);
     sexp_fcall_return(tmp1, 1)
     break;
   case SEXP_OP_FCALL3:
     _ALIGN_IP();
     sexp_context_top(ctx) = top;
+    sexp_context_last_fp(ctx) = fp;
     tmp1 = ((sexp_proc4)sexp_opcode_func(_WORD0))(ctx, _WORD0, 3, _ARG1, _ARG2, _ARG3);
     sexp_fcall_return(tmp1, 2)
     break;
   case SEXP_OP_FCALL4:
     _ALIGN_IP();
     sexp_context_top(ctx) = top;
+    sexp_context_last_fp(ctx) = fp;
     tmp1 = ((sexp_proc5)sexp_opcode_func(_WORD0))(ctx, _WORD0, 4, _ARG1, _ARG2, _ARG3, _ARG4);
     sexp_fcall_return(tmp1, 3)
     break;
@@ -1075,6 +1079,7 @@ sexp sexp_apply (sexp ctx, sexp proc, sexp args) {
   case SEXP_OP_FCALLN:
     _ALIGN_IP();
     sexp_context_top(ctx) = top;
+    sexp_context_last_fp(ctx) = fp;
     i = sexp_opcode_num_args(_WORD0);
     tmp1 = sexp_fcall(ctx, self, i, _WORD0);
     sexp_fcall_return(tmp1, i-1)